I have developed an application for my company that uses an HTTPS connector to synchronize data between the handheld and a server in our DMZ. The data transfer works flawlessly for our users on Verizon 8830 devices with BIS. According to my server logs, our users with T-Mobile Pearls and BES are not even getting through to it, ie. the server never sees the request come through from the Pearl devices. The service is T-Mobile Internet and no APN is specified under the TCP Advanced Options.

I know the Pearls have access to the server as the server also hosts the application for OTA and I can download and install on my Pearls via HTTPS connection through the browser with no problem. It is only when the app itself tries to initiate the HTTPS connection that the server never sees the request.

My GUESS at this point is that it has something to do with BES vs. BIS but a half day of research and talking to (un)technical support at T-Mobile has yielded no results. Hoping someone here can validate (or not) the issue and point to a solution other than switching service ;)